[RE-wrenches] Remote battery disconnects

[Alex MeVay]

> Oh, yeah, the charge controller blowing up thing:  Does anyone have any factual data to share on this?

Although our controllers are probably smaller than what you would be
considering in this discussion, surviving a load dump (suddenly
disconnected battery) is an engineering requirement for us, and likely
would be for other responsible MFG's on this list (boB?).  The charge
controller can either handle full input voltage on the output, or
there is a comparator that will shut the controller down instantly
when the output voltage gets too high.

The only time we run into trouble during a load dump is if there is
another charger that is less well-behaved, such as an alternator,
running at the same time.  This most commonly happens on sailboats,
when someone turns off the ignominious battery switch with the engine
still running.  The alternator spikes the battery line from 12V up to
50-100V+ before the alternator regulator can respond, and the charge
controller (and other electronics aboard) might not survive.

Tangential to this conversation, it seems battery switches cause our
marine and RV customers way more problems than they solve.  It seems
important to have one, but I wish they were a little more towards the
break-glass-in-case-of-emergency end of the accessibility spectrum.

Thank as always, Wrenches, for the information you share and high
level of discourse.

Alex MeVay

Genasun * Blue Sky Energy * http://sunforgellc.com